1. to study the different T cell subtypes (Th1, Th2, Th17 and Treg) in the lower airways of healthy subjects and clinically different asthma patients, based on a non-invasive procedure of sputum induction. Patients will be different in function of age, in relation to the trigger (eg aspirin, without or with association with polyposis), without or with underlying atopic sensitization or different in the type of underlying inflammation (eosinophilic vs neutrophilic). This T cell pattern will become the basis of molecular phenotyping in the patients.